1. Field of the Invention
The invention concerns an electronic module for a rotary electrical machine.
The present invention applies to any type of polyphase rotary electrical machine, synchronous or asynchronous, such as alternators or alternator starters, and also whether it is a case of electrical machines for motor vehicles and driven for example by belt, with cooling by air, liquid or any other solution that can be envisaged.
2. Description of the Related Art
In a motor vehicle comprising a thermal engine and a rotary electrical machine such as an alternator starter, such an electrical machine comprises for example, non-limitatively:                a rotor comprising a field winding into which an excitation current is brought, and        a stator comprising a polyphase winding.        
The alternator starter functions in motor mode or in generator mode. It is a so-called reversible machine.
In generator or alternator mode, the machine converts a rotation movement of the rotor driven by the thermal engine of the vehicle into an electric current induced in the phases of the stator. In this case, a bridge rectifier connected to the phases of the stator rectifies the sinusoidal induced current into a DC current in order to supply consumers on the vehicle such as a battery.
On the other hand, in motor mode, the electric machine serves as an electric motor for rotating, via the shaft of the rotor, the thermal engine of the vehicle. It converts electrical energy into mechanical energy. In this case, an inverter converts a DC current coming from the battery into an alternating current for supplying the phases of the stator in order to rotate the rotor.
Control signals are used to determine the operating mode of the rotary electrical machine (motor mode or generator mode).
In a first prior art, in the document WO 02/060038 (corresponds to U.S. Pat. No. 6,692,278), the bridge rectifier/inverter comprises a plurality of transistors integrated in an electronic box. The electronic box is connected to the rotary electrical machine via a three-phase connecting cable. This solution is bulky having regard to the space available under the engine bonnet, and expensive because of the cable and its assembly, which represents a not insignificant additional cost.
In a second prior art, in the document DE 102004007395 A1, electronic components are used that are outside an external peripheral band. These components comprise power connection ends that are also inside the band. The band comprises internal partitions in which metal power interconnection tracks are molded on. These power tracks connect the components via their power ends to the battery so as to supply them. The band is positioned on the rear bearing of the machine. This solution proves to be problematic because of the cross-sections of the power interconnection tracks, which are too small compared with the current necessary, around 150 A in alternator mode and 600 A on starting, for the application of an alternator or alternator starter so that the tracks reach an excessively high temperature.